The present disclosure relates generally to equipment utilized and operations performed in conjunction with a subterranean well and, in an embodiment described herein, more particularly provides for mitigating shock produced by well perforating.
Attempts have been made to model the effects of shock due to perforating. It would be desirable to be able to predict shock due to perforating, for example, to prevent unsetting a production packer, to prevent failure of a perforating gun body, and to otherwise prevent or at least reduce damage to various components of a perforating string. In some circumstances, shock transmitted to a packer above a perforating string can even damage equipment above the packer.
In addition, wells are being drilled deeper, perforating string lengths are getting longer, and explosive loading is getting greater, all in efforts to achieve enhanced production from wells. These factors are pushing the envelope on what conventional perforating strings can withstand.
Unfortunately, past shock models have not been able to predict shock effects in axial, bending and torsional directions, and to apply these shock effects to three dimensional structures, thereby predicting stresses in particular components of the perforating string. One hindrance to the development of such a shock model has been the lack of satisfactory measurements of the strains, loads, stresses, pressures, and/or accelerations, etc., produced by perforating. Such measurements can be useful in verifying a shock model and refining its output.
Therefore, it will be appreciated that improvements are needed in the art. These improvements can be used, for example, in designing new perforating string components which are properly configured for the conditions they will experience in actual perforating situations, and in preventing damage to any equipment.